ATI Radeon X850XT-Platinum Edition
 

On average, the X800XT-PE is about 5% to 10%, give or take a couple
percentage points faster than the X800XT. Assuming you are lucky enough to
grab an ATI X800XT-PE, the difference will be smaller. Basically, if
benchmarks are your thing, the X850XT-PE is the fastest card ATI has to
offer.

http://www.viperlair.com/reviews/video/ati/r4xx/x850pe/